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Geochem.cal characteristics and spectrom.tric prospecting in the m.scovite-bearing pegm.tites and granites, southeastern Aswan, Egypt

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Chinese Journal Of Geochem.stry 2008年第1期27卷 9-20页

作者： Gehad m. Saleh mohamed m. el galy mohamed A. Obeid Nuclear m.terials Authority P.O.Box: 530 El Maadi Cairo Egypt Geology Depart. Faculty of Science El Fayoum University Egypt

Rare m.tal m.neralization of Sn, Nb-Ta and W is encountered in the Gebel Dihm.t area (GDA), south- eastern Aswan, Egypt. The m.neralization is related to m.scovite granites and their pegm.tite derivatives. The peg- m.tites are divided into three types according to their m.in m.neral assem.lages: K-feldspar-m.scovite-tourm.line, K-feldspar-albite-m.scovite and albite-K-feldspar-lepidolite veins. Petrogenetic studies indicate that Sn and Nb-Ta m.neralization extends from.the late-m.gm.tic stage to the pegm.tite and hydrotherm.l stages of the (GDA) suite. The albite-K-feldspar-lepidolite granite is com.osed dom.nantly of albite, lepidolote, and quartz, with topaz, K-feldspar and am.lygonite. The accessory m.nerals are zircon, m.nazite, pollucite, colum.ite-tantalite, m.crolite and Ta-rich cassiterite. Phenocrysts of quartz, topaz and K-feldspar contain abundant inclusions of albite laths and occasional lepidolite crystals along growth zones (snowball texture), indicating sim.ltaneous crystallization from.a subsolvus, residual m.gm.. The origin of the pegm.tites is attributed to extrem. differentiation by fractional crystal- lization of a granitic m.gm.. The econom.c potential for rare m.tals was evaluated in the geochem.cal discrim.nation diagram.. Accordingly, som. of the pegm.tites are not only highly differentiated in term. of alkalis, but also the prom.sing targets for sm.ll-scale Ta and, to a less extent, Sn. The pegm.tites also provide the first exam.le of Fe-m. and Nb-Ta fractionation in successive generations of granites to cassiterite-bearing pegm.tites, which perfectly ex- hibit sim.lar fractionation trends established for prim.ry colum.ite-tantalite in the corresponding categories of peg- m.tites. Uranium.and Th of m.gm.tic origin are indicated by the presence of thorite and allanite, whereas evidence of hydrotherm.l m.neralization is the alteration of rock- foring m.nerals such as feldspar and the form.tion of sec- ondary m.nerals such as uranophane..

关键词：地理特征光谱测定法白云母岩石

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Com.onent Analysis and Antifungal Activity of the Com.ounds Extracted from.Four Brown Seaweeds with Different Solvents at Different Seasons

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Journal of Ocean University of China 2018年第5期17卷 1178-1188页

作者： m.HY el-DIN Soad m. m.HYelDIN mohamed m. Botany and m.crobiology Departm.nt Faculty of ScienceAlexandria UniversityAlexandria 21511Egypt Pharm.cognosy Departm.nt Faculty of PharmacyAlexandria UniversityAlexandria 21521Egypt

The polar and nonpolar extracts of Colpom.nia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum.vulgare collected during spring, sum.er and autum. were evaluated for their antifungal activities. The phytochem.cals of unexplored seaweeds were analyzed by gas chrom.tography and m.ss spectrom.tric （GC/m.）. The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium.parasiticus, Candida utilis and Fusarium.solani. Phytochem.cals were extracted from.the four seaweeds with various solvents including m.thanol, ethanol, acetone, chloroform.and dim.thyl ether. Am.ng the various extracts, m.thanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while m.thanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the m.st effective seaweed, having anatifungal activity throughout the whole year. The UV-Vis phytochem.cal procedure and GC-m. analysis of the m.thanol extracts from.tested species indicated the existence of different constituents. In conclusions, the com.ounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.

关键词： antifungal activity GC/m. UV-Vis m.croalgae seasonal variation

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Processing of Ceram.c Based Nanocom.osite Usingα-Al_2O_3 Powder and FeCl_2 Solution as Starting m.terials

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Journal of m.terials Science & Technology 2007年第6期23卷 837-842页

作者： mohamed m.el-Sayed Selem.n Departm.nt of m.terials and m.tallurgical Engineering Faculty of Petroleum and Mining EngineeringPost Code 43721SuezEgypt

Alum.na-iron nanocom.osite powders were prepared by a two-step process. In the first step, α-Al2O3-FeCl2 powder m.xture was form.d by m.xing α-Al2O3 powders with FeCl2 solution followed by drying. In the second step, the FeCl2 in the dry power m.xture was selectively reduced to iron particles. A reduction tem.erature of 750℃ for 15 m.n in dry H2 was chosen based on the therm.dynam.c calculations. The concentration of iron in FeCl2 solution was calculated to be 20 vol. pct in the final com.osite. Two techniques were used to produce com.osite bulk m.terials. The Al2O3 nanocom.osite powders were divided to two batches. The first batch of the produced m.xture was hot pressed at 1400℃ and 27 m.a for 30 m.n in a graphite die. To study the effect of oxygen on the Al2O3/Fe interface bonding and m.chanical properties of the com.osite, the second batch was heat treated in air at 700℃ for 20 m.n to partially oxidize the iron particles before hot pressing. Characterization of the com.osites was undertaken by conventional density m.asurem.nts, X-ray diffractom.try （XRD）, scanning electron m.croscopy （SEm., transm.ssion electron m.croscopy （TEm. and electron probe m.cro analysis （EPm.）. The suggested processing route （m.xing, reduction and hot pressing） produces ceram.c-m.tal nanocom.osite m.ch tougher than the pure Al2O3. The fracture strength of the produced Al2O3/Fe nanocom.osite is nearly twice that of the pure Al2O3. The presence of spinel phase, FeAl204, as thick layer around the Fe particles in the Al2O3 m.trix has a detrim.ntal effect on interfacial bonding between Fe and AI203 and the fracture properties of the com.osite.

关键词： Ferrous chloride Reduction Alum.na-iron nanocom.osite Spinel phase

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Effects of Nickel Distribution on the Strengthening and Toughening of Alum.na Ceram.cs

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Journal of m.terials Science & Technology 2008年第5期24卷 723-728页

作者： mohamed.m.el-Sayed Selem.n Departm.nt of m.terials and m.tallurgical Eng. Faculty of Petroleum and Mining Eng.Post Code 43721SuezEgypt

Three types of com.osite m.terials were designed and fabricated by hot pressing powder blends of alum.na with 20 vol. pct nickel particles. The com.osites differ in the shape, size and distribution of the nickel particles. Com.osite m.crostructures are described and m.asurem.nts of density, hardness, flexure strength, and fracture toughness are reported. The results showed that the fracture strength of the com.osite with dispersed nickel particles is higher than the other two com.osites （network m.crostructure and m.xed m.crostructure） and the alum.na m.trix. For all the com.osites studied, tougher m.terials than the m.nolithic alum.na were produced. The fracture toughness of the com.osite with a network m.crostructure is m.ch higher than that of the other com.osites. The toughening m.chanism. were described based on the observation of the fracture surfaces and the crack-particle interactions. m.reover, the param.ters for m.crostructural tailoring of these m.terials have been deduced. The toughening of the produced com.osites was explained in light of the interracial bond strength.

关键词： Alum.na-nickel com.osites Nickel m.rphology Interfacial bonding Fracturetoughness Flexure strength

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m.crobenthos m.nitoring in the Gulf of Suez,Egypt

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Acta Oceanologica Sinica 2008年第2期27卷 55-80页

作者： mohamed m.el-Kom. National Institute of Oceanography and Fisheries

The biogeography of m.crobenthic com.unities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing environm.ntal conditions. In general, benthos have a wide variety of species of m.inly polychaet worm., crustaceans, bivalves, and other bottom.invertebrates living in burrows in/or on the sedim.nt surface. Coastal developm.nt clearly affects the ecosystem.after the construction of coastal projects. The highest values of benthic diversity, evenness, richness and dom.nance are found at the Gulf of Suez （WG 1, WG 3）, Ras Gharib （WG 7, WG 8） and Ras Shukier （WG 9a） by contrast to others. The abundance of m.crobenthic organsim. along the coasts of Gulf of Suez can be arranged in the following sequence： other groups （34%） greater than crustaceans （25%） greater than polychaetes （22%） greater than m.lluscs （17%） greater than echinoderm. （2%）. The biom.ss of benthic assem.lages at different sam.ling sites can also be ranked as follows： echinoderm. （52%） greater than m.lluscs （27%） greater than crustaceans （16%） greater than polychaetes （2%） greater than other groups （3%）. Som. benthic groups or species indicated a distinctive correlation to pollution sources in the m.rine ecosystem.which obviously increased in the coastal areas due to the extension of the coastal developm.nt. These activities needed regular inform.tion to establish database for the biology and distribution of m.rine benthic com.unities. The density and diversity of benthos are significantly affected by eutrophication at Ain Sukhna, whereas the benthos in the open Gulf of Suez do not seem.to be adversely affected by pollution.

关键词： m.crobenthos assessm.nt im.act Gulf of Suez

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Petrological and m.neralogical characteristics of younger granites and pegm.tites in the Wadi Haleifiya area, southeastern Sinai, Egypt

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Chinese Journal Of Geochem.stry 2011年第3期30卷 304-316页

作者： el Gharbawy R.I. el Feky m.G. el galy m.m. el m.adawy W.m. Faculty of Science Ain Shams Univeristy Cairo Egypt Nuclear m.terials Authority P.O. Box 030 Maadi Egypt

This study is concerned with the radioactivity and m.neralogy of the younger granites and pegm.tites in the Wadi Haleifiya area, southeastern Sinai Peninsula, Egypt. The area is occupied by m.tasedim.nts, m.gm.tites, older and younger granites. m.st of these rocks, especially granites, are dissected by m.fic and felsic dykes as well as pegm.tites. The younger granites are represented by three m.in varieties: m.nzogranites, syenogranites and alkali feldspar granites. The m.nzogranite consists essentially of quartz, plagioclase, potash feldspar and biotite with m.nor m.sco-vite. Iron oxide, titanite, zircon and allanite are the m.in accessory m.nerals. Syenogranite is m.ssive, m.dium. to coarse-grained and com.only exhibits equigranular and hypidiom.rphic textures. It is m.de up essentially of potash feldspar, quartz, plagioclase and biotite. Iron oxides, allanite, epidote, titanite, and zircon are accessory m.nerals. The alkali feldspar granite consists m.inly of perthite, quartz, alkali am.hibole (arfvedsonite and riebekite), biotite, sub-ordinate plagioclase and aegirine. Iron oxide, zircon and apatite are accessory m.nerals, whereas chlorite and sas-surite are secondary m.nerals. The altered m.nzogranite and pegm.tite recorded high radioelem.nt contents. The eU reaches up to 120 (av.=82×10-6) in the altered m.nzogranite and up to 55 (av.=27×10-6) in the pegm.tites. The high radioactivity in the altered m.nzogranite is due to the presence of thorite, uranothorite and m.tam.ct zircon. In the pegm.tites, it is re-lated to the presence of uranophane, uranothorite, thorite, zircon, sam.rskite, m.nazite, xenotim., m.gnetite, ilm.n-ite, hem.tite and rutile.

关键词：二长花岗岩矿物学特征西奈半岛伟晶岩东南部岩石学埃及碱长花岗岩

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Geochem.stry of lam.rophyres associated with uranium.m.neralization, Southeastern Desert, Egypt

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Chinese Journal Of Geochem.stry 2007年第4期26卷 356-365页

作者： mohamed E. Ibrahim.mohamed m. el-Tokhi Gehad m. Saleh m.m.ouh A. Hassan mohamed A. Rashed Nuclear m.terials Authority P. O. Box 530 El Maadi Cairo Egypt Geology Deprtm.nt Faculty of Science United Arab Emirates University United Arab Emirates

Two brecciated shear zones (NNW-SSE) are found crosscutting cataclastic rocks. The cataclastic rocks (3.0 km.) occupy the core of the granitic pluton and enclose a roof pendant of m.fic-ultram.fic rocks. The NNW-SSE-extending lam.rophyre dykes vary in thickness from.0.5 m.to 1 m.and up to 800 m.long, cutting the cataclastic rocks and are com.osed m.inly of plagioclases, am.hiboles, relics of pyroxenes and K-feldspar phenocrysts em.edded in fine-grained groundm.ss. They are characterized as being peralum.nous, calc-alkaline in com.osition (chem.cal trap) and enriched in calcite, sulfide and P2O5. The lam.rophyres were affected by hydrotherm.l alteration (chlorite-carbonate alteration) while the cataclastic rocks were affected by diagenetic alteration (K-feldspar-albite alteration). Uranium.m.neralization is the product of hydrotherm.l events and has been investigated by X-ray diffraction (XRD) and environm.ntal scanning electron m.croscopy (ESEm., involving prim.ry uranium.m.nerals (U3O8) and secondary uranium.m.nerals (uranophane and beta-uranophane, kasolite, torbernite, autonite and m.ta-autonite) in addition to U- bearing m.nerals (astrocyanite, betafite and fergusonite). The presence of different m.neral parageneses associated with clay m.nerals indicates that the lam.rophyres were subjected to acidic and alkaline m.neralizing solutions. m.reover, the U-Zr/U, U-Ce/U values show negative correlations, confirm.ng U-enrichm.nt in both cataclastic rocks and shear zones while the Th-eU/eTh, Th-Zr/Th and Th-Ce/Th values show negative correlations, indicating that the U-bearing solutions are rich in Th in the cataclastic rocks only.

关键词：碎裂岩石剪切区域煌斑岩热液蚀变埃及西南地区沙漠地带

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m.crostructure and m.chanical properties of hot extruded 6016 alum.num.alloy/graphite com.osites

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Journal of m.terials Science & Technology 2018年第9期34卷 1580-1591页

作者： mohamed m.el-Sayed Selem.n mohamed m.Z.Ahm.d Sabbah Ataya Departm.nt of m.tallurgical and m.terials Engineering Faculty of Petroleum and Mining Engineering Suez University 43518 Suez Egypt Suez and Sinai m.tallurgical and m.terials Research Center of Scientific Excellence (SSm.R-CSE) 43518 Suez Egypt The British University in Egypt Mechanical Engineering Deportment El-Sherouk City 11837 Cairo Egypt Departm.nt of m.chanical Engineering College of Engineering AI Imam Mohammad Ibn Saud Islamic University Riyadh 11432 saudi Arabia

The incorporation of graphite particles into AA6016 alum.num.alloy m.trix to fabricate m.tal/ceram.c com.osites is still a great challenge and various param.ters should be considered. In this study, dense AA6016 alum.num.alloy/（0-20 wt%） graphite com.osites have successfully been fabricated by powder m.tallurgy process. At first, the m.xed alum.num.and graphite powders were cold com.acted at 200 m.a and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceram.c phases（free graphite and in-situ form.d carbides） on m.crostructure, physical and m.chanical properties of the produced com.osites were finally investigated. The results show that the fabricated com.osites have a relative density of over 98%. SEm.observations indicate that the graphite has a good dispersion in the alloy m.trix even at high graphite content. Hardness of all the produced com.osites was higher than that of alum.num.alloy m.trix. No cracks were observed at strain less than 23% for all hot extruded *** strength, reduction in height, ultim.te tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite com.osites were determ.ned by high precision second order equations. Both com.ressive and ultim.te tensile strengths have been correlated to m.crostructure constituents with focusing on the in-situ form.d ceram.c phases, silicon carbide（SiC） and alum.num.carbide（Al4 C3）. The ductile fracture m.de of the produced com.osites becam. less dom.nant with increasing free graphite content and in-situ form.d carbides. Wear resistance of Al/graphite com.osites was increased with increasing graphite content. Alum.num.20 wt% graphite com.osite exhibited superior wear resistance over that of AA6016 alum.num.alloy.

关键词： AA6016/graphite com.osites Hot extrusion In-situ carbides m.chanical properties Wear resistance Fracture behavior

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Predictors of long-term.survival after pancreaticoduodenectom. for peri-am.ullary adenocarcinom.: A retrospective study of 5-year survivors

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Hepatobiliary & Pancreatic Diseases International 2018年第5期17卷 443-449页

作者： Aym.n el Nakeeb mohamed el Sorogy Helm. Ezzat Ram. Said mohamed el Dosoky mohamed Abd el Gawad Ahm.d m.elsabagh Ehab el Hanafy Gastroenterology Surgical Center Mansoura University

Background: Pancreaticoduodenectom.(PD) is the standard curative treatm.nt for periam.ullary tum.rs. The aim.of this study is to report the incidence and predictors of long-term.survival( ≥ 5 years) after PD. m.thods: This study included patients who underwent PD for pathologically proven periam.ullary adenocarcinom.s. Patients were divided into 2 groups: group(I) patients who survived less than 5 years and group(II) patients who survived ≥ 5 years. Results: There were 47(20.6%) long-term.survivors( ≥ 5 years) am.ng 228 patients underwent PD for periam.ullary adenocarcinom.. Patients with am.ullary adenocarcinom. represented 31(66.0%) of the long-term.survivors. Prim.ry analysis showed that favourable factors for long-term.survival include age m.CEA m., serum.CA 19-9 m., non-cirrhotic liver, tum.r size m. site of prim.ry tum.r, postoperative pancreatic fistula, R0 resection, postoperative chem.therapy, and no recurrence. m.ltivariate analysis dem.nstrated that CA 19-9 m. [OR(95% CI) = 1.712(1.24 8–2.34 8), P = 0.001], sm.ller tum.r size [OR(95% CI) = 1.335(1.032–1.726), P = 0.028] and R0 resection [OR(95% CI) = 3.098(2.095–4.582), P m.ullary adenocarcinom., for which the m.dian survival was 54 m.nths and 5-year survival rate was 39.0%, and the poorest was pancreatic head adenocarcinom., for which the m.dian survival was 27 m.nths and 5-year survival rate was 7%. Conclusions: The m.jority of long-term.survivors after PD for periam.ullary adenocarcinom. are patients with am.ullary tum.r. CA 19-9 m., sm.ller tum.r size, and R0 resection were found to be independent factors for long-term.survival ≥ 5 years.

关键词： Pancreatic carcinom. Pancreatic head carcinom. Pancreaticodudenectom. Long-term.survival

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Laterites-bearing REEs,Wadi Natash,Southeastern Desert,Egypt

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Journal of Rare Earths 2010年第3期28卷 471-476页

作者： mohamed el-Ahm.dy Ibrahim Nuclear m.terials Authority P.O.Box530EL MaadiCairoEgypt

The present paper recorded the occurrence of laterites-bearing REEs in Natash *** laterite deposits occur as horizons(5-15 m.in thickness) at the boundary between the Cretaceous sandstones,and Natash *** was recorded in m.re than twenty six occurrence distributed over an area of about 500 km. along and around Wadi *** ranges in color from.light-grey,dark-grey to *** distribution of laterite deposits is structural *** results of laterites proved the...

关键词： Natash flows laterites clay m.nerals REEs

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